A contact lens and its manufacturing method

Abstract

A contact lens includes a lens formed by mixing a lens main component and one or more colored materials. The lens has a central portion and a peripheral portion. The central portion has a first thickness distribution, and the peripheral portion has a second thickness distribution. A thickness difference exists between the first thickness distribution and the second thickness distribution, such that the central portion forms a light-transmitting area and the peripheral portion forms a colored area reflecting the color of the one or more colored materials.

Description

Technical Field

[0001] The present invention relates to a contact lens, in particular to a single-layer structured colored contact lens and a preparation method thereof. Prior Art

[0002] Among contact lens products, tinted contact lenses allow the wearer to alter their eye color for aesthetic or cosmetic purposes. Essentially, these lenses are made by adding a tinted portion to a transparent contact lens, creating a tinted effect without affecting the wearer's vision.

[0003] Most of the methods use two structures to achieve this. One is to use pad printing or inkjet printing to print the dye ink onto the contact lens. Related technologies are disclosed in previous applications such as US20060181676A1, US20020057416A1, US20030048409A1, US20220365371A1, US20200376787A1, and US20230182423A1. The other is to use a multi-layer structure, such as disposing a dye layer on a light-transmitting layer, or forming a sandwich structure, as disclosed in previous applications such as US20220291525A1, US8721073B2, US8322852B2, US20230384482A1, US20220365371A1, and US20240288713A1.

[0004] In addition to the formation of the contact lenses themselves, the aforementioned colored contact lenses require multiple manufacturing processes, which not only increases manufacturing time and cost, but also easily leads to yield issues. Summary of the Invention

[0005] The present invention provides a contact lens comprising a lens formed by mixing a main lens component and one or more colored materials. The lens has a central portion and a peripheral portion. The central portion has a first thickness distribution, and the peripheral portion has a second thickness distribution. There is a thickness difference between the first thickness distribution and the second thickness distribution, so that the central portion forms a light-transmitting area and the peripheral portion forms a colored area reflecting the color of the one or more colored materials. The thickness of a peripheral area surrounding an interface between the central portion and the peripheral portion varies smoothly with radius, and the light-transmitting area and the colored area have different transmittances.

[0006] The present invention also provides a method for preparing a contact lens, comprising the following steps: first, dispensing an uncured lens composition into a cavity of a mold, the lens composition comprising a main lens component and one or more colored materials mixed and formed. Next, curing the lens composition within the mold to produce a contact lens. The mold comprises a front curved surface mold and a back curved surface mold that contact the lens composition. The front curved surface mold and the back curved surface mold are configured to create a thickness difference between a first thickness distribution in a central portion of the contact lens and a second thickness distribution in a peripheral portion of the contact lens. The thickness difference causes the first thickness distribution to form a light-transmitting region and the second thickness distribution to form a colored region reflecting the color of the one or more colored materials. The thickness of a region surrounding an interface between the central portion and the peripheral portion varies smoothly with radius, and the light transmittance of the light-transmitting region and the colored region differs. Simple diagram description

[0007] FIG1 is a front view of a contact lens according to an embodiment of the present invention. FIG2 is a schematic cross-sectional view of FIG1. FIG3 is a schematic diagram of multiple examples of the present invention. FIG4 is a schematic diagram of thickness distribution of an example of the present invention. Implementation Method

[0008] It should be understood that the terms used in the description of the various embodiments herein are for the purpose of describing particular examples only and are not intended to be limiting. Unless the context clearly indicates otherwise, or unless a number of elements is intended to be limited, the singular forms "a," "an," and "the" as used herein include the plural forms. It will be further understood that the terms "include" and / or "comprise," when used herein, indicate the presence of the recited features, elements, and / or components, but do not preclude the addition or presence of one or more other features, elements, components, and / or groups thereof. Indefinite and definite articles include the singular and plural, unless the context clearly indicates otherwise. As used herein, "about" means that the value referred to as "about" includes the recited value plus or minus 1% to 10% of that value, for example, 1% to 5%.

[0009] The present invention relates to a contact lens, also known as a contact lens, which refers to an ophthalmic device that can be placed on the cornea of ​​an individual's eye. The contact lens can be used to correct, improve or modify the user's vision and / or provide cosmetic or therapeutic benefits, including wound healing, drug or nutritional delivery, diagnostic assessment or monitoring, ultraviolet light absorption, visible light or glare reduction, or combinations thereof.

[0010] The contact lens may be a soft lens, a hard lens, or a hybrid lens having different physical, mechanical, or optical properties, including but not limited to modulus, water content, light transmission, or combinations thereof. The contact lens may be in a dry state, where the dry state refers to a soft lens in its pre-hydration state or a hard lens in its storage or use conditions, or in a wet state, where the wet state refers to a soft lens in its hydrated state.

[0011] According to one aspect of the present invention, the contact lens is a lens formed by mixing a main lens component and one or more colored materials. The main lens component may include one or more reactive monomers, one or more cross-linking agents, one or more initiators or starters, and one or more additives or solvents.

[0012] The reactive monomer can be a hydrogel, silicone hydrogel, rigid breathable material, or any other material that can serve as a primary component of a contact lens. The initiator (or initiator) can be a photoinitiator, a thermal initiator, or a chemical initiator. Exemplary hydrogels include, but are not limited to, hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA), N-vinyl pyrrolidone (NVP), N,N'-dimethylacrylamide (DMA), N,N'-diethylacrylamide, N-isopropylacrlamide, 2-hydroxyethyl acrylate, vinyl acetate, N-acryloymorpholine, 2-dimethlaminoethyl acrylate, or combinations thereof.

[0013] The colored material can be any organic or inorganic pigment or dye suitable for contact lenses, or a combination thereof. Any colored material can be used in the present invention, as long as the colored material can provide a colored element that is small enough to scatter a small amount of visible light at a certain concentration. In some examples, the colored element is less than about 1 micron in size. A pigment refers to a powdered substance suspended in a liquid in which it is not dissolved. The size of the pigment can be less than or about 5 microns. A dye refers to a substance that is soluble in a solvent and used to impart color. It can be translucent and absorbs but does not scatter light. Exemplary colored materials include, but are not limited to, all colorants or combinations thereof listed in 21CFR part 74 and 21CFR part 75 by the U.S. Food and Drug Administration.

[0014] Referring to Figures 1 and 2 , according to one embodiment of the present invention, the contact lens 10 is circular. However, in other embodiments, the contact lens 10 may be any commonly used contact lens shape, such as an elliptical or truncated circular shape. The contact lens 10 comprises a central portion 11, a peripheral portion 12, and a peripheral portion 13. In one embodiment, the central portion 11 may correspond to the pupil region of an individual's eye and / or to a portion of the eyeball and the sclera of the individual's eye. For example, the diameter of the central portion 11 measured from a center point 16 may be between 2 mm and 12 mm, and the peripheral portion 12 may correspond to a portion of the eyeball and the sclera of the individual's eye. The inner diameter of the peripheral portion 12 is equal to the outer diameter of the central portion 11 and may be, for example, between 2 mm and 12 mm. The outer diameter of the peripheral portion 12 may be between 13 mm and 15 mm.

[0015] The contact lens 10 can be planar or non-planar. In this embodiment, the contact lens 10 has a front curved surface 14 and a back curved surface 15. The back curved surface 15 is configured to contact one eye of a wearer when worn, with the front curved surface 14 facing the back curved surface 15. The front curved surface 14 and the back curved surface 15 are designed to provide geometric structures required for specific optical properties, including but not limited to spherical, aspherical, and cylindrical refractive powers, wavefront aberration correction, corneal topography correction, and combinations thereof.

[0016] In one example, the contact lens 10 is manufactured from a single composition. It should be understood that the single composition includes multiple chemical substances. The single composition means that the chemical composition (concentration or ratio of each chemical substance) of each portion of the contact lens 10 (the central portion 11, the peripheral portion 12, and / or the edge portion 13) is substantially equal or similar, that is, the chemical substances are uniformly dispersed. In some examples, it can be interpreted that the chemical composition of the contact lens 10 has not been intentionally changed.

[0017] In one example, in the contact lens 10, the total weight of the colored material accounts for no more than 5 wt.% of the weight of all components (the main component of the lens and the colored material), for example, between 0.001 wt.% and 5 wt.%, between 0.001 wt.% and 4 wt.%, between 0.001 wt.% and 3.5 wt.%, between 0.001 wt.% and 3 wt.%, etc.

[0018] In another example, the contact lens 10 comprises at least two components in a single-layer structure. Specifically, the central portion 11 and the peripheral portion 12 are respectively a first component and a second component. The first component may contain only the lens main component, or be primarily composed of the lens main component and contain a small amount of the tinting material. The second component may contain only the tinting material, or be primarily composed of the tinting material and contain a small amount of the lens main component. For example, in the first component, the total weight of the tinting material accounts for no more than 5 wt.% of the weight of all components (the lens main component and the tinting material). In the second component, the total weight of the tinting material accounts for between 0.003 wt.% and 5 wt.%, and the concentration of the tinting material in the second component is greater than that of the tinting material in the first component. The concentration may be expressed as a weight percentage.

[0019] Regardless of the above composition, the contact lens 10 is a lens, or it can be defined as being formed through a single process, such as a single shaping and curing process, but possibly one or more injection processes. For example, the contact lens 10 is not a two-layer structure, a sandwich structure, or a multi-layer structure. In some aspects, the contact lens 10 lacks an ink layer, that is, a coloring layer, a pigment layer, or a dye layer used to produce a specific color. However, this does not preclude the contact lens 10 from undergoing further processing; in other words, the contact lens 10 may be further printed with other layers or combined with other layers.

[0020] The present invention utilizes a combination of component design and thickness variation to enable the contact lens 10, with a single composition, to produce at least partially transparent and colored regions at varying thicknesses. FIG3 shows a plurality of contact lenses 20a, 20b, 20c, 20d, 20e, 20f, and 20g each exhibiting different colors of the peripheral portion 12 through varying thicknesses. Furthermore, the transmittance of the transparent region differs from that of the colored region.

[0021] The central portion 11 and the peripheral portion 12 have a first thickness profile and a second thickness profile, respectively. The term "thickness profile" is used here because these portions may have multiple thicknesses rather than a single thickness. For example, the thickness of the central portion 11 and / or the peripheral portion 12 may vary along a radial, circumferential, or other lateral direction. The difference between the first thickness profile of the central portion 11 and the second thickness profile of the peripheral portion 12 is sufficient to ensure that the central portion 11 forms a region that has no effect on the wearer's visual acuity. The region of the central portion 11 may be clear, while the peripheral portion 12 forms a colored region that reflects the color of the one or more colored materials. In this example, the central portion 11 is a light-transmissive, non-colored region. This light-transmissive, non-colored region refers to a region that, when the contact lens 10 is worn on an individual's eye, does not alter the natural color of the individual's eye as observed by an ordinary observer. Accordingly, the central portion 11 is an optical zone, and the peripheral portion 12 and / or the edge portion 13 may be a non-optical zone. However, in some examples, the peripheral portion 12 and / or the edge portion 13 may also be an optical zone.

[0022] The difference between the first and second thickness distributions referred to herein can have various possibilities. In one example, the range of the second thickness distribution is greater than the range of the first thickness distribution, meaning that any thickness in the second thickness distribution is greater than any thickness in the first thickness distribution, or in other words, the second thickness distribution is absolutely greater than the first thickness distribution. In another example, the average thickness of the second thickness distribution may be greater than the average thickness of the first thickness distribution. The present invention is not limited to this example; as long as the difference allows the central portion 11 to form the region that has no effect on the wearer's visual acuity and the peripheral portion 12 to form the colored region, it is sufficient. From another perspective, there is a color difference between the central portion 11 and the peripheral portion 12, and this color difference requires the central portion 11 to form the region that has no effect on the wearer's visual acuity.

[0023] In one example, the first thickness distribution of the central portion 11 is between 0.01 mm and 0.25 mm, and the second thickness distribution of the peripheral portion 12 is between 0.05 mm and 0.5 mm, and the thickness of the second thickness distribution is greater than the first thickness distribution. In one example, the difference can be any one or a combination of the following conditions:

[0024] a. Any thickness of the surrounding portion 12 is greater than any thickness of the central portion 11;

[0025] b. The average thickness of the peripheral portion 12 is greater than the average thickness of the central portion 11;

[0026] c. The thickness distribution on the peripheral portion 12 is different from the thickness distribution on the central portion 11; and

[0027] d. The one or more maximum thicknesses on the peripheral portion 12 are greater than the one or more maximum thicknesses on the central portion 11 .

[0028] In one example, the thickness distribution described above can be the variation in thickness of the central portion 11 and / or the peripheral portion 12 with radius. FIG. 4 shows a schematic diagram of the thickness distribution of the central portion 11, the peripheral portion 12, and the edge portion 13 in one example. (a) shows a schematic diagram of the thickness profile of the contact lens 10, while (b) shows the variation in thickness of the contact lens 10 corresponding to (a) with increasing radius. This example illustrates the aforementioned conditions c and d. In some examples, the variation in thickness with radius refers to the difference in the profiles of the front curved surface 14 and the back curved surface 15, as shown in the thickness distribution diagram in FIG. 4 .

[0029] The thickness variation of the central portion 11 may vary depending on the optical purpose. In the example of vision correction, the thickness of the central portion 11 decreases as the radius increases from the center point 16. However, the present invention is not limited to this. The thickness of the central portion 11 may increase as the radius increases, or may vary in multiple steps (e.g., first increase and then decrease, or vice versa). The thickness of the peripheral portion 12 may be fixed or variable, such as increasing or decreasing as the radius increases. In one example, the thickness of the peripheral portion 12 is sufficient to form the colored area. On the other hand, since the peripheral portion 12 is not an optical zone and is primarily used to provide color, the thickest portion of the contact lens 10 is located in the peripheral portion 12, meaning that the contact lens 10 has a maximum thickness located in the peripheral portion 12. The edge portion 13 connects to the outermost edge of the peripheral portion 12 and its thickness gradually decreases to zero. In one example, the thickness of a peripheral area of ​​a junction 17 between the central portion 11 and the peripheral portion 12 changes smoothly with the radius, for example, in (b) of FIG. 4 , the peripheral area of ​​the junction 17 between the central portion 11 and the peripheral portion 12.

[0030] According to one aspect of the present invention, the central portion 11 and the peripheral portion 12 formed based on the thickness difference can also be defined by absorbance, rather than clarity or color. For example, the central portion 11 and the peripheral portion 12 each have a first absorbance and a second absorbance. For the central portion 11 of the optical zone, the first absorbance refers to the absorbance for light with a wavelength between 380 nm and 780 nm. For the peripheral portion 12 of the colored zone, the second absorbance refers to the absorbance for light with a wavelength of a specific color. The first absorbance is less than the second absorbance, ranging from 0 to 30%, and the second absorbance is between 10% and 99%. The absorbance of the edge portion 13 is not limited. It should be understood that the first absorbance of the central portion 11 may have one or more values, and the second absorbance of the peripheral portion 12 may have one or more values, and the ratio of a maximum value (ABS-2 max) of the second absorbance of the peripheral portion 12 to an average value (ABS-1 avg) of the first absorbance of the central portion 11 is at least greater than a specific value X, as shown in the following formula:

[0031] X is a preset value not less than 1, which can be an integer or a non-integer. In one example, X is 2. In some examples, X is an integer or a non-integer between 1 and 10.

[0032] As used herein, the term "clear" refers to being visibly transparent and non-opaque, for example, having a light transmittance of about 80% or greater, about 85% or greater, about 90% or greater, about 95% or greater, or about 99% or greater. In one example, the clear area is colorless, while in other examples, the clear area is transparent, translucent, a transparent color, a translucent color, a combination of the foregoing, or a combination of an opaque color and the foregoing.

[0033] As used herein, the term non-opaque refers to a transparent or translucent color or a portion of a lens that is not tinted or tinted with a transparent or translucent color.

[0034] As used herein, the term opaque refers to a color that allows an average light transmittance of 0% to about 50%, and preferably 7% to about 50%, within the range of 380 nm to 780 nm. The term translucent, as used herein, refers to a color that allows an average light transmittance of about 50% to about 85%, and preferably about 65% to about 85%, within the range of 380 nm to 780 nm.

[0035] The colored area refers to an area that, when the contact lens 10 is worn on an individual's eye, alters the natural color of the individual's eye when the contact lens 10 is not worn, as observed by an ordinary observer. The colored area herein may be designed to enhance or alter the appearance of the individual's eye, particularly the color of the individual's eye. In one example, the surrounding portion is a solid color band covering the color of the limbal area of ​​the lens wearer, such as a masked color (i.e., an opaque color). In other examples, the surrounding portion may be transparent, translucent, or partially transparent. The colored area may be completely opaque, so that when viewed by an ordinary observer, the colored area appears to be the colored area itself. If the colored area is translucent or partially transparent, it means that the colored area combines with the natural or normal color of the individual's eye to form a different color. In other aspects, the colored region herein may also be designed to absorb or prevent radiation within a specific wavelength range, including but not limited to ultraviolet (UV) radiation and high energy visible light (HEVL), and the colored region has a light absorption effect.

[0036] The colored area is a colored portion that is not printed or has one or more additional layers. It may be a continuous or discontinuous pattern. The pattern may contain a single color or multiple colors, including any color such as blue, green, gray, brown, black, yellow, red, or a combination thereof, and may have any hue, chroma, saturation, intensity, brightness, or value. The pattern may have a geometric appearance such as dots, islands, spirals, starbursts, spokes, spikes, stripes, radial patterns, or zigzags.

[0037] 10: Contact lenses 11: Central part 12: surrounding part 13: Edge 14: Front curved surface 15: Back curved surface 16: Center point 17: Meeting 20a, 20b, 20c, 20d, 20e, 20f, 20g: contact lenses

Claims

1. A contact lens comprising: A lens formed by mixing a main lens component and one or more colored materials, the lens having a central portion and a peripheral portion, the central portion having a first thickness distribution, and the peripheral portion having a second thickness distribution, wherein there is a thickness difference between the first thickness distribution and the second thickness distribution, so that the central portion forms a light-transmitting area and the peripheral portion forms a colored area reflecting the color of the one or more colored materials, wherein the thickness of a peripheral area surrounding an interface between the central portion and the peripheral portion varies smoothly with a change in radius, and the light-transmitting area and the colored area have different transmittances.

2. The contact lens of claim 1, wherein: The central portion and the colored region are of substantially the same composition.

3. The contact lens of claim 2, wherein: The total weight of the colored material of the lens accounts for no more than 5 wt.% of the total weight.

4. The contact lens of claim 1, wherein: The concentration of the colored material in the peripheral portion is greater than the concentration of the colored material in the central portion.

5. The contact lens of claim 4, wherein: The total weight of the colored material in the surrounding portion accounts for 0.003 wt.% to 5 wt.% of the total weight of the surrounding portion.

6. The contact lens of claim 1, wherein: The central portion and the colored area respectively have a first absorbance for light with a wavelength between 380 nm and 780 nm and a second absorbance for light with a wavelength corresponding to a specific color, and the first absorbance is smaller than the second absorbance.

7. The contact lens of claim 6, wherein: The first absorbance is between 0 and 30%, and the second absorbance is between 10% and 99%.

8. The contact lens of claim 6, wherein: The first absorbance and the second absorbance meet the following conditions: ABS-2 max is a maximum value of the second absorbance, ABS-1 avg is an average value of the first absorbance, and X is a preset value not less than 1.

9. A method for preparing a contact lens, comprising the steps of: dispensing an uncured lens composition into a cavity of a mold, the lens composition comprising a main lens component and one or more colored materials mixed and formed; and curing the lens composition in the mold to obtain a contact lens; wherein, The mold includes a front curved surface mold and a back curved surface mold that contact the lens component, and the front curved surface mold and the back curved surface mold are configured so that there is a thickness difference between a first thickness distribution of a central part of the contact lens and a second thickness distribution of a peripheral part of the contact lens, and the thickness difference causes the first thickness distribution to form a light-transmitting area and the second thickness distribution to form a colored area reflecting the color of the one or more colored materials, wherein the thickness of a surrounding area of ​​a junction between the central part and the peripheral part changes smoothly with the change of radius, and the transmittance of the light-transmitting area and the colored area is different.

10. The preparation method according to claim 9, wherein: The central portion and the colored region are of substantially the same composition.

11. The preparation method according to claim 9, wherein: The total weight of the colored material of the lens accounts for no more than 5 wt.% of the total weight.

12. The preparation method according to claim 9, wherein: The concentration of the colored material in the peripheral portion is greater than the concentration of the colored material in the central portion.

13. The preparation method according to claim 9, wherein: The total weight of the colored material in the surrounding portion accounts for 0.003 wt.% to 5 wt.% of the total weight of the surrounding portion.

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